WordPress performance testing seems simple: run a load test, check numbers and assess if the site is fast, but results depend on the hosting infrastructure.

Software Testing Magazine

WordPress performance test results are heavily influenced by the underlying hosting infrastructure, not just the application itself. Key factors include CPU clock speed (single-threaded PHP favors higher GHz over more cores), storage type (NVMe vs SATA with up to 5.88x IOPS difference), database engine choice (MariaDB outperforms MySQL and Aurora in transactional benchmarks), web server software (LiteSpeed handles ~5,100 req/s vs Apache's ~900), and caching layers like OPcache and Redis. Cloud burstable instances (AWS T2/T3) can invalidate benchmarks when CPU credits run out mid-test. Geographic server location also affects TTFB regardless of server-side optimizations. Understanding these variables is essential for producing reliable, reproducible benchmarks.

How Hosting Infrastructure Affects WordPress Performance Testing